Floating Valves

[Focker420]

I have a question about floating valves and if there is any way to make it so your valves can use the high rpm to the fullest potential. Kind of like vtech but without using the hydraulic lifters to compensate?

TY
NATE

 

[Quasimondo]

Stronger valve springs.

From Wikipedia:
Valve float is a condition which occurs when the valves on an internal combustion engine do not return to the fully closed position under high RPMs due to the inability of the valve springs to overcome the momentum of the valvetrain. Stiffer valve springs can help prevent this but only at the expense of increased friction losses.

Various techniques have been used to offset the effect of stiffer springs, such as dual spring and progressive sprung valves.

 

[GSGoinFast]

I have a question about floating valves and if there is any way to make it so your valves can use the high rpm to the fullest potential. Kind of like vtech but without using the hydraulic lifters to compensate?

TY
NATE

Frankly, I don't have a clue to what you are talking about, but I don't think you have a problem with valve float.

 

[Focker420]

it is like the higher the rpms it just doesn't have the same pull and i was wondering if i do turbo it wouldn't it be even worse with the extra hp.

 

[alex]

Well you will have valve float in higher RPMs with aftermarket cams on stock springs. That is why you want to upgrade your springs when upgrading cams.

 

[VelocitàPaola]

Frankly, I don't have a clue to what you are talking about, but I don't think you have a problem with valve float.

For some reason, that's one of the funniest reponses I've read in a while...

But, I concur. I don't think you have a problem with valve float whatsoever: it's really something you don't encounter unless you've screwed with the cams, like Alex said.

 

[XMasta19]

Well you will have valve float in higher RPMs with aftermarket cams on stock springs. That is why you want to upgrade your springs when upgrading cams.

http://www.dsmtuners.com/forums/showthread.php?t=230615

 

[dr1665]

it is like the higher the rpms it just doesn't have the same pull and i was wondering if i do turbo it wouldn't it be even worse with the extra hp.

i got header/and pipping to the muffler, Cold air intake,throttle body spacer,Msd ignition coil,short throw shifter and bushings. under drive pully set.Duel friction clutch.Safc 2 ecm piggy back

ported cylinder head, New crane cam sticks, 3 angle valve grind,adjustable cam gears. no botton end till i have all parts for turbo upgrade.

Details on these cam sticks? Details on at what engine speed you think you might be experiencing valve float? Details on this "ecm piggy back?" Details on how you've set up your SAFC? Details on your cam timing?

You need to provide a lot more infomation if you want any information you can use. If you have the mods listed in your profile, then you need to let us know, specifically, how everything is dialed-in.

Nothing personal, but you don't exactly come across as someone who knows what they're doing. If nothing else, I would suggest you do the following steps:

1. Remove the SAFC.
2. Remove the "ecm piggy back."
3. Set both cam gears to 0*.

Then see what you get.

 

[Focker420]

W/e think what u want but are u a Journey Man? I'm not here to nit pick or argue so my cam gears are already at zero dyno guy had no idea what hes doing so he didn't adjust my safc is the ecm piggy back and the settings on the high throttle is my worried about the floating valves and i can't understand why the dyno guy last time set my high throttle to dump alot of fuel at like 3500rpm then takes away to like 6000rpm then dumps again i just need to find a good tuner to tinker with my car. All mods are in my profile any questions just ask.

 

[FORMONTOYA]

As stated, we would need information about the cams and springs used plus what redline rpm you plan on running. Without that information, we will all be guessing.

1) If you're upgrading the cams, you should upgrade the springs, period. Why halfa$$ it at this point?

2) If you're not exceeding the 7500rpm rev limiter (4G63T) you will not float a valve unless things are severely worn out.

3) If you're planning on going so high in the rpm band to float valves, you have a lot more work in front of you than you think.

4) The engineers that designed your engine (and mine) have factored in margins of safety so this kind of stuff doesn't happen....unless things are severely worn out, or you mod the sh!t out of it.

Does anything else need to be said?

 

[Turbocharged]

W/e think what u want but are u a Journey Man? I'm not here to nit pick or argue so my cam gears are already at zero dyno guy had no idea what hes doing so he didn't adjust my safc is the ecm piggy back and the settings on the high throttle is my worried about the floating valves and i can't understand why the dyno guy last time set my high throttle to dump alot of fuel at like 3500rpm then takes away to like 6000rpm then dumps again i just need to find a good tuner to tinker with my car. All mods are in my profile any questions just ask

Valves will float at very high rpm's. You stated that your car does not pull in the upper rpm's, so you have no business spinning the motor that high anyways.

What the hell is a "crane cam stick"?!

 

[Quasimondo]

Are you stoned 420 or is english not your native language?


Valves will float at very high rpm's. You stated that your car does not pull in the upper rpm's, so you have no business spinning the motor that high anyways.

What the hell is a "crane cam stick"?!

Crane cams, perhaps?

If you're not exceeding your redline, you probably don't have an issue with floating valves. If you have aftermarket cams that have a more aggressive profile, you should've invested in a good set of aftermarket valve springs to go with them.

I've checked around because I wasn't sure, but my quick google skills show the 420A engine to be an interference engine like the 4G63's (feel free to correct me if I'm wrong), so if you did have a problem with valve float, chances are you would've broken something by now from the pistons repeatedly slamming into the valves.

From the limited amount of information you've given us, it could be anything from picking the wrong cams that give you low end grunt at the sacrifice of top end power, poor tuning that kills your top end, improperly dialed in cams, etc.

We need more information, like everybody's been asking for. What kind of camshafts do you have? What engine speed is the power loss? What are your low-throttle and high-throttle AFC settings?

 

[dr1665]

EDIT:
Nevermind. Not worth it. I'll just ignore this one from here on out.

 

[GSGoinFast]

W/e think what u want but are u a Journey Man? I'm not here to nit pick or argue so my cam gears are already at zero dyno guy had no idea what hes doing so he didn't adjust my safc is the ecm piggy back and the settings on the high throttle is my worried about the floating valves and i can't understand why the dyno guy last time set my high throttle to dump alot of fuel at like 3500rpm then takes away to like 6000rpm then dumps again i just need to find a good tuner to tinker with my car. All mods are in my profile any questions just ask but don't be a prick about it!!!!

That could be your problem. You can't really dump fuel in with a s-afc on our cars.

Don't call Brian a prick, name calling is not a way to get ahead on this or any forum, especially someone with Brian's knowledge and reputation. Members won't be so willing to help next time.

 

[Focker420]

Ok so like i said not here to bicker of nit-pick so don't be offended u just insultided me.

As for info It seems like a power loss at high rpm say like 6500 to my redline i don't like to take it past 7000 only redlines to 7250 so there is no power gain at that rpm just gets louder. My thinking tells me your right about the safc tuning and its probly way off but how do i tell or adjust to tell were i need to be. I have rebuilt the head with aggressive cams from crane cams. And just got the cam gears but not tuned i got new springs, retainers, seals, valves.When i got it rebuilt so its been beefed up and can take the high rpm but why is there such little gain for me and what is the normal redline on my car?.

Nate.

 

[dr1665]

Okay. Putting bullshit behind us...

If you are concerned you might be losing some valuable information on the SAFC, write down the settings before you reset things to zero. Please tell us which cams you got from Crane - 0012, 0016, 0018, etc.. I'm thinking you're still running the stock ECU as most of us are. Above 6500rpm, it's going to start pulling timing on you, at which point it will seem like it's just getting louder, while the car stops pulling. I ran the AFX/R ECU for a while, with the 7800rpm rev limiter, and the timing advance it offered meant the car would pull all the way to that point and still have more to go. I could feel it. Going back to the stocker in preparation for the MSnS, the car turned into a complete turd. Crower 2 power doesn't come on until around 4000rpm and the stupid ECU dumbs it back down above 6000, so it just gets really loud and feels like it's slowing down.

As for making any power with the SAFC, if it's any use to you at all at this point, would be to leave it zeroed-out and strap the car to a dyno again. Get a wideband O2 reading for a pull or two and see where your fuel curve is in need of some help. I would theorize that installing larger injectors to provide more fuel everywhere and using the SAFC to lean things out where you need less fuel might help you out, but the SAFC can only do so much and, even then, you're still not going to be doing anything to address the stock ECU pulling timing on you in the top end. I'd seriously suggest looking into MSnS for your car if you are fully built. Pick up a wbO2 sensor and let the MSnS keep your fuel trims in check while locking in ignition timing where you want it to be in the top end. You can also raise the rev limiter on it if you like.

Hope this helps.

 

[Focker420]

Okay. Putting bullshit behind us...

If you are concerned you might be losing some valuable information on the SAFC, write down the settings before you reset things to zero. Please tell us which cams you got from Crane - 0012, 0016, 0018, etc.. I'm thinking you're still running the stock ECU as most of us are. Above 6500rpm, it's going to start pulling timing on you, at which point it will seem like it's just getting louder, while the car stops pulling. I ran the AFX/R ECU for a while, with the 7800rpm rev limiter, and the timing advance it offered meant the car would pull all the way to that point and still have more to go. I could feel it. Going back to the stocker in preparation for the MSnS, the car turned into a complete turd. Crower 2 power doesn't come on until around 4000rpm and the stupid ECU dumbs it back down above 6000, so it just gets really loud and feels like it's slowing down.

As for making any power with the SAFC, if it's any use to you at all at this point, would be to leave it zeroed-out and strap the car to a dyno again. Get a wideband O2 reading for a pull or two and see where your fuel curve is in need of some help. I would theorize that installing larger injectors to provide more fuel everywhere and using the SAFC to lean things out where you need less fuel might help you out, but the SAFC can only do so much and, even then, you're still not going to be doing anything to address the stock ECU pulling timing on you in the top end. I'd seriously suggest looking into MSnS for your car if you are fully built. Pick up a wbO2 sensor and let the MSnS keep your fuel trims in check while locking in ignition timing where you want it to be in the top end. You can also raise the rev limiter on it if you like.

Hope this helps.

\
K i will get the exact cam for u in a sec. i wanted to let u know that i don't think bigg injectors is what i need because i had a running rich problem before i put in the new cam gears. And thats why i think the dyno guys has set my safc way off coarse but i got the code to go away when i put the new gears in (might be timing related) so now i tryed to get the dyno guy to tune but he was all worried cause the car steering wheel turned 90 degrees when he started to accel. did 1 pull in forth don't know why but the dyno specs where wosre than the last time i dyno'd it and i have put in some further mods since like the gears and underdrive and pully set, so sould have got some gain but didn't why?
Also what is MSnS? i also plan on getting my injectors and whatever else when i get turbo kit.

 

[dr1665]

i wanted to let u know that i don't think bigg injectors is what i need because i had a running rich problem before i put in the new cam gears. And thats why i think the dyno guys has set my safc way off coarse

Ah, but where were you running rich? Running an aggressive cam profile will result in reduced vacuum at idle, and the ECU will dump in fuel to compensate. If anything, you only need SAFC to lean things out so the car will not flood out/stall during cold starts. Otherwise, high-end portwork can actually tax your stock injectors at the upper limits of the tach, sending you borderline lean. You need a wideband O2 reading during your dyno pulls to determine how your AFRs look across the powerband.

the dyno guy . . . was all worried cause the car steering wheel turned 90 degrees when he started to accel.

Sounds like an alignment problem of some sort - either the car is not aligned properly or the car is not aligned properly on the dyno.

did 1 pull in forth don't know why

Fourth gear is a 1:1 ratio. Any other gear and you're getting a mechanical multiplier which will yield false numbers.

i have put in some further mods since like the gears and underdrive and pully set, so sould have got some gain but didn't why?

If the car is not sticking to the rollers the way it should, you will not get accurate readings. Furthermore, cam gears will do nothing by themselves. You can tune for more power, but incorrect tuning can result in a loss of power. Pullies allow more power to transfer to the wheels, but if you've got fuel/timing issues, the engine is not running at optimal settings. Add to that an inability to properly run the car on the dyno and you have a great formula for seeing poor results.

The dyno only shows what kind of power the wheels are transferring. If you can't get the wheels to hook up right, then you're not going to see anything you care about.

Also what is MSnS? i also plan on getting my injectors and whatever else when i get turbo kit.

MSnS is MegaSquirt'n'Spark. This is discussed in much detail in the engine management forum of this website. If you have plans to make any serious power with your car, either NA or turbocharged, you will need more than larger injectors and some shitty SAFC to make it happen. Just so you know.

Now, all that said, I think I have been more than generous in trying to help you out. It's time to step up your efforts and address the issues with your posting style. It sounds like you are on the verge of being one of those major players in the community who has the fully built engine, turbocharges that engine, and gets things tuned so he can bring something more to the table than the typical, lazy high school kid with an AEM intake and Greddy catback. I say this to you with all due respect, sir, unless English is a second language to you, you would find that you get a lot more respect if you would just take the time to use punctuation, capitalization and a little spelling from time to time. Your words on this forum are the bulk of your reputation in this environment.

If you know your shit, then by all means, step up to that next level and show us.